Whether sexual or not obviously the two of them shared a huge emotional thing,
in the AC trailer Tifa does mention about how close the two of them got towards the final battle and also feels that the emotions have faded somewhat over the past two years.

It is wrong to kill because someone will be sad. Same with why someone should be good, because you will hurt someone and if you do and if everyone is connected it will comeback to you. Karma is a bitch.
(\_/)
(O.o)(>

naw... i don't think cloud and tifa had sex. all tifa did was lay her head on his shoulder and all cloud did was sit there and stare out into space.dat must have been why cloud said nothing but".....". don't forget, cloud wanted tuh leave but it was tifa who said "just a little longer."

That could be a possibility, but Tifa was always embarrassed about her emotions (like if you have the dating scene with her, she doesnt tell cloud how she feels, and says it would be easier for aerith but not for her). So she could have just been embarrased by the fact that they were there watching her just sit and talk to cloud about how she feels.

why cant the situation be plutonic, and have to be sexual? why analyze every bit of conversation and make it sexual?! why sit down and think about it all?! go outside.

p.s. couldnt the black out just be the next day after they fell asleep?

That could be a possibility, but Tifa was always embarrassed about her emotions (like if you have the dating scene with her, she doesnt tell cloud how she feels, and says it would be easier for aerith but not for her). So she could have just been embarrased by the fact that they were there watching her just sit and talk to cloud about how she feels.

why cant the situation be plutonic, and have to be sexual? why analyze every bit of conversation and make it sexual?! why sit down and think about it all?! go outside.

p.s. couldnt the black out just be the next day after they fell asleep?